(1) Field of the Invention
The present invention relates generally to circular knitting machines and, more particularly, to a circular knitting machine adapted to knit and take-up a very large roll of fabric.
(2) Description of the Prior Art
Historically, circular knitting machines have employed take-up rolls for receiving knitted fabric which are capable of holding between about 50 to 250 lb. rolls. Subsequent fabric processing, including bleaching and dyeing require larger continuous quantities of fabric for efficient handling. In order to achieve longer continuous quantities of fabric, fabric from small fabric rolls were stitched together to form a continuous cloth. Problems associated with stitching smaller fabric sections together include varying product quality and properties, like inconsistent courses per inch (CPI), stretch and shrinkage, stretch and distortion of fabric wales, and lower productivity due to machine downtime for removing and loading new fabric rolls.
Additionally, prior art circular knitting machines are incapable of controlling tension at the fabric take-up roll for larger fabric roll sizes; as the fabric roll diameter increased, tension in the fabric and yarn increased, thereby causing breaks which result in increased machine downtime, higher waste, and lower fabric quality.
One prior art solution was to provide a dual roll fabric tension system between the needle sinker assembly and fabric roll. However, dual roll fabric tension systems fail to adjust for the high levels of tension generated by large fabric rolls as the diameter increases. Therefore, as the fabric tension builds-up, the fabric rips off the needles, causing machine breaks and needle damage. In addition, this system used a conventional storage feed mounting ring which required the operator to use a ladder or catwalk to attend to many of the machine functions.
Thus, there remains a need for a circular knitting machine with a tension-controlled large roll take-up assembly which can form very large continuous fabric rolls for improved quality in subsequent processing, including bleaching and finishing operations while, at the same time, permits the operator to attend to most machine functions without the need for a ladder or catwalk.